Basic Restorative Flashcards
Which acids are mainly produced by the bacterias?
Lactic
Propionic
Acetic
What is the of caries?
A process affecting the mineralised tissues of the teeth which is causes the action of microorganism on fermentable carbohydrates to produce acids
Which acid is the most damaging?
Lactic acid
Which sugar is the most carigigenic?
Sucrose
Which bacteria are found in health?
Mainly gram pos facultative bacteria
S sanguis
S gordonii
Which bacteria are mainly found in fissure caries?
S sanguis and mitis
What are the common sites to develop caries?
Pits and fissures
Approximate surfaces
Root surface
What are rh four requisites to caries?
Bacterial plaque
Bacterial substrate
Susceptible tooth surface
Time
Which bacteria are involved in caries mainly?
Strep mutans
Lactobacillus sp.deep lesions
Acrinomycosis for root caries
How do primary enamel caries appear?
White spot lesion
Brown spot
What are the microscopic appearance of primary enamel caries?
IEBS
Initiation
Enamel destruction
Bacterial invasion
Secondary enamel caries
What is in the initiation phase of enamel and how porous are they?
TDBS
Normal enamel: 0.1% Translucent zone: 1% Dark zone : 2-4% Periphery : 5% Body zone: 25% Surface zone : 1%
What is Sedondary enamel caries?
Enamel adjacent to dentine is less resistant to caries possibly due to the branching of dentinal tubules
WHat are the zones of dentine caries?
SCZA
Superficial area : just beneath breached enamel
Central area: necrosis and destruction
Zone of penetration : tubules penetrated by bacteria
Advancing front : demineralised but not infected
What are the types of dentine?
Primary: bulk of dentine around pulp and also known as cicrumpulpal dentine
Sedondary dentine: develops after root formation and is continuos wit primary but slower rate of formation. Less regular than primary
Tertiary dentine: reactive to stimuli . Deposited either odontoblasts or replacement cells from pulp. Tubular pattern very irregular
T/F cementum rapidly decaclfies?
T
What are the risk factors for caries?
SES age Diet Local factors Fluoride Saliva pH
How can we assess the activity of a carious lesions?
Matt or shiny
Colour
Consistency
What would caries that felt matt more likely indicate?
More active and indicated amount of pores
What does colour indicate?
Poor indicator but may indicate arresting
What does the consistent indicate?
Soft and leathery are more active
What are the defence mechanisms of the pulp dentine complex?
Tubular scleorsis: this is when the tubules become complety filled with calcified material and increases with age
Reactionary dentine
Inflammation of pulp and pulpits
Where does the pulp come from?
Dental papilla
Which caries has seen the biggest reduction on orevelance?
Smooth
How much do fissure caries account for new lesions?
84%
How does fissure caries start?
Bilaterally along walls as inverted cone shape
What does tooth brushing prevent?
Smooth surface caries
What is the reasonnfor change in caries?
Improved awareness
Use of fluorides
When does fissure caries occur?
Two school of thought
- Occlusal caries incidence peaks during and immediately after eruption
- Occlusal caries incidence remains high and unremitting
Which ways can we diagnose caries?
Invasive and non invasive
What are the invasive caries diagnosis techniques?
Diagnostic cavity
Enamel biopsy
What are the non invasive caries detection?
Probe Visual inspection Magnification Radiographs Trans illumination Electronic methods
What is the problem with using a probe in fissure caries?
False positives as probe may stick in fissure due to normal anatomy
Misses dentinal caries
Possibility of breaking the soft surface zone and introduce cariogenic bacteria
Unreliable
How does visual inspection work?
Clean dry tooth
Must see staining and se calcification around the fissure
How does magnicficationwork?
Fissure caries detection improves and times 4 is thought to be the best
What magnification does an intrs oral camera use?
X40
What magnification does an operating microscope use?
X16
How helpful is radiographs in fissure caries ?
Only useful for occult lesions but otherwise not great since
- Superimposition or buccal and Palatal enamel
- Often only seen when caries into dentine
- Small changes in X-ray tube head can make small lesions disappear
How effective is trans illumination?
Good for interproximal caries on ANTERIOR teeth
But POOR in POSTERIOR teeth
What must the ambient light be for trans illumination?
Low
How will a caries free tooth appear compared to a caries tooth within trans illumination?
Caries free will glow
What is an example of trans illumination?
FOTI
Compared to x ray how good is FOTI ?
17% enamel lesions detected
48% of dentine
Low sensitivity
What are the electronic methods for caries detection based on?
Carious teeth contain pores of enamel which saliva can pass through and this conduct small electrical currents
How effective are the electronic methods for caries detection?
HIGH SENSITIVITY !!!!! Can be used to monitor progress
What is the diode laser fluoresce?
Uses a laser of 680nm
Carious tooth structure is diff to normal
Fluorescence changes are measured and converted to an analogue scale
Low reading: sound
High reason: caries
80% sens and spec
But no diagnostic threshold and mainly used for occlusal lesions in conjunction with other technique
How does vista proof work?
High energery violet light used
Hat wave,length of light is used in vista proof?
405nm
What does vista proof show?
Porphyrin metabolites show red
Natrual tooth is green
What is th best way for carious detection using non invasive ways?
Clean dry tooth
Visual inspection
Light
When would invasive methods for caries detection be used?
High risk population or STRONG suspicion of caries in that tooth
What are the treatment options for fissure caries?
Observe Laser therapy Ozone Sealane t Amalgam Composite Inlay
When would you observe for fissure caries?
You don’t since cannot see it well
How does laser therapy work for fissure caries?
CO2 laser
Causes carbonate and mg depletion
Reorganises apatite structure
Raises pulp temp by not more than 1 degrees
What materials can you use for a sealant restoration?
GIC Composte Fissure sealants Compomer Dentine adhesive
How does a sealants restoration work?and how much surface does it occupy?
Treatment of the enamel and dentine caries in a discrete part of the fissure pattern
Occupies 5%
Amalgam occupies 25%
What are the advantages of sealant restoration?
Minimal cavity prep
Tooth not weakened
Aesthetic
Simulatanous prevention
What do we polish restrorstions?
For aesthetics,minimise plaque retention, and gingival irration, remove over hangs,
What are the options for increasing amalgam retention?
Slots: no greater than 1mm Groves Boxes Dovetails Steps Circumfrential slots Dentine pins Bonded amalgams Amalgapins
How effective is the Circumfrential slot?
Very
Same resistance as 4 pins but more sensitive to displacement during matrix band removal
What are amalgam pins?
Amalgam is used for the retention and similar placement to cone tonal pins
How’s does the resistance to displacement for the amalgam pins compare to the conventional prins?
Same
What are the dimsjonas for amalagmpins?
- 5-2 mm deep
0. 8mm diameter
How wide and deep do your slopes and steps need to be?
- 0 mm wide
1. oo tall
What are bonded amalgams?
Where you use a bonding agent to aid retention of amalgam
T/F the bond strength between the amalgam and bonding agent is weaker than that of the tooth and bonding agent?
T
T/F there is less stress on the bond between amalgam and bonding agent than compared to composte?
T
What type of bonding agents would you use for bonded amalgams?
Autopolymersising agent
What to dentine pins provide?
Mechanical retention and resistance
How do dentine pins work?
Mechanical interlocking of amalgam into undercuts on the pin
What is the pins retention dependant upon?
Resiliency and firmness of dentine
What are the three types of dentine pins?
Self threading
Friction locked
Cemented
T/F self threading are less retentive than friction locked?
F
Self threading are the most retentive
What is the optimum depth of the dentine pins into dentine?
2-3mm
What is the optimum length of pin into amalgam?
2mm
T/F larger diameter pins are more retentive?
T
How many pins per missing cusp should be placed?
1 or marginal ridge/line angle
What is the maximum of pins in a tooth?
4
How far apart should pins be and what are the other requirement when placing pins?
5mm apart
1mm inside DEJ
1mm inside external Root is apical tonCEJ
2mm into dentine and amalgam
2mm from opposing tooth
How much dentine between pin and ADJ?
1mm
What angle should you place pins?
90 degree
What can you cost the pins in?
MDP Panavia or
4 META
How much amalgam is needed ontop of the ion for replacing a cusp?
2.5mm
What speed hand piece do you use for pins?
200rpm clockwise
What are the problems with pin placement?
Voids around pin Pins bent Lose pin Pin at amalgam surface Pulp exposure Root perforation
What are the matrix bands available?
Siqveland
Tofflemire
Autommatrix
Copper band
How long to extensive amagalsm last?
14.6 years
Where do class 2 lesions occur?
Least one of the interproximal surfaces on posterior teeth staters just below contact point
How can we classify caries lesions?
E1: outer hand of enamel E2: inner half of enamel D1: 0.5mm into dentine D2: more than 0.5 but not within 0.5mm of pulp D3: more than 0.5mm within pulp
How can you diagnose interproximal caries?
Visual inspection Radiographs Laster fluoresce eg diagno dent Light transmission Electrical resistance Temporsry tooth separation
How long does it take caries to reach ADJ in adults vs children?
Adults: 6 yrs
Kids: 4 yrs
What are the options for class 2?
Class 2 with key Class 2 with self retentive box Tunnel prep MOD Tunnel prep Pre fabricated eg inlay
What percentage of class 2 amalgams have fractured cusps?
13%
Occur at any age but most frequently affect molars
Which types of restorations have the biggest number of cusp fracture?
MOD
How does the tunnel prep work?
Intact marginal ridge
What was the tunnel prep initially deigned for?
GIC
What are the problems with tunnel prep?
Cannot visualise whole lesions
Not sure if cairies free
Cannot assess the strength of remsning tooth
Secondary carie within 3yrs
What are thr indications for posterior composite?
Small and moderate sized class 2
Patient allergic to metal s
Unsupported enamel may be strengthened by acid etch technqie
Not possible to obtain retention
What are the contr indications to posterior composites?
Patients with high caries risk Cavities where cannot get isolation Multiple large restrorstions with cuspal contact Bruxism Allergies
What are thr problems with large class 2 composites?
Wear
Fracture
Microleakage
Cuspal flexure
What is the survival rate for amalgam vs composite?
15 yrs amalgam
6 yrs composite
What is blacks classification for caries?
Class 1: pit and fissure
2: mesial and distal premolar and molar
3: mesial and distal incisors and canine
4: involving incisal edge
5: occurring at cervical third
What are the contemporary caries classification?
Site
Size
What are the caries by site classification?
Site 1: pits fissures and enamel defects on occlusal or other smooth surfaces
Site 2: approximate surfaces for ant and post teeth
Site 3: cervical third of all teeth and any exposed roots
What is the classification by size?
0: initial lesion
1: minimal surface cavitation
2: moderate dentine
3: enlarged beyond moderate
4: extensive caries with loss of cusp
Why may anterior teeth need restoring?1
Caries Colour Fracture Wear Developmental disorder
Where do class 3 lesions start?
Just at or below the contact point in the mid labial Palatal third
T/F the incidence for class 3 is higher than pit and fissure caries?
F Becaus 1-anterior teeth more accessible for OH 2: narrower contact ares 3: increased use of fluoridated tooth paste
Which patients are class 3 more common in?
Mouth breathers
Imbricated teeth
How do you diagnose class 3?
Can see once into dentine as a darkness
What diagnostic methods can we use for class 3?
Probe Visual Radiographs Trans illumination Shred floss
What probes are used for detecting class 2 and class 2 lesions?
Brialt and Weston
Nee to use a light pressure
How can you use trans illumination in class 3 lesions?
Light off dental mirror
FOTI
What are the ways of restoring class 3?
Palatal
Labial
When would we bevel class 3 cavity?
When the cavity extends to an area that is visible then bevel
Advantages: end on etching of enamel prisms, increases surface ares for bond, blends composte better, reduces micro leakage
BUT: increase cavity size
What lining materials can we use in class three?
Dentine bonding agents
Light cured GIC
CaOH
What is an alternative to class three prep?
Tunnel prep
How can you gain retention for class 4?
Cervical groove in dentine
Enchant
Dentine pins
Bevel
Which matrices can you use for class 4?
Polyester : straight or curved of incisal corner
Cellulose acetate
What is the dis with cellulose acetate strip?
Reacts with composte
Too thick and bulky
Tear
